Area rugs, for instance Oriental rugs, are commonly laid over wall-to-wall carpeting or other carpets, or over decorative wood flooring, to achieve desired esthetic effects. When such rugs are laid over carpets the rug may tend to slip or move in one direction due to the alternating compression and release of the fibers in the underlying carpet caused by normal traffic. Thus the rug and furnishings placed on it move from their desired position. Additionally the rug may become creased or wrinkled instead of flat. Such rugs may also slip on the polished surfaces of a decorative wood floor. Such movements detract from the esthetics of the room and may cause slipping and tripping risks.
Rug underlays have been proposed as a solution to such problems, for instance the rug underlays disclosed by Mussallem in U.S. Pat. No. 4,504,538 and U.S. Pat. No. 4,985,279. The underlay typically consists of a light-weight non-woven mat, comprised of filamentary fibers, needle-punched into a coarse thin mat. Needle-punching is commonly used to compress fibrous mats into a felt-like material. Mussallem discloses that any natural or synthetic fiber may be used in the underlay, but that synthetic fibers such as polyolefin, nylon, polyester, acrylic polymers, etc., are preferred. Needle-punching can also be used to embed a woven mesh in such a non-woven mat to strengthen and stiffen the mat. The needle-punched mat is then treated with an emulsion adhesive, such as a synthetic rubber latex, on at least one side and preferably both sides. The adhesive is then cured. The adhesive properties of the underlay effectively secures it to the underlying rug or underlying surface and prevents movement. The underlay adhesive coating is selected to provide both the necessary adhesive strength to prevent slippage or movement and a sufficiently low peel strength so that the rug may be easily and reversibly removed from the underlying surface for cleaning or other purposes.
The prior art discloses a method to render the secondary backing of a carpet substantially impervious to liquids by treatment with repellent compositions, such as fluorochemicals, silicone-based compositions, oils, waxes, and/or hydrophobic acrylate resins. Typically area and Oriental rugs are not treated by such processes and are therefore permeable to liquids.
If water-based or oil-based liquids are spilled on a rug placed over a carpet or decorative wood floor, the underlying material may become stained and deteriorate. Water-based spills may also transfer dyes from the rug to the underlying material. Other water-based spills may contain colored materials, e.g., colored drinks or coffee, or contain other undesirable components, e.g., urine, which can soak through to the underlying material. Oil-based liquids, e.g., mineral oil, baby oil, kerosene, or alcohol, may penetrate to the underlying material with potential undesirable effects. Cleaning aids applied to the rug may similarly pass through the rug and adversely affect the underlying material. Oil-in-water emulsions, e.g., milk or lotions, and water-in-oil emulsions, e.g., dairy spreads, are examples of spills requiring a barrier substantially and simultaneously impervious to both water-based and oil-based spills.
It would be desirable if a treatment could be applied to the underlay which would create a substantially impervious barrier to liquids between the rug and the underlying material. Such a treatment must not interfere with the adhesive surfaces of the underlay, and ideally would be readily incorporated into the manufacturing process for the underlay.